Green chemistry breakthrough for renewables at Monash

May 14, 2019

Electrolytic water splitting is widely understood to be the most feasible method for the production of green hydrogen fuel as a versatile means of storage and long-range transportation for the intermittent renewable energy.

The development of water splitting technologies is important to Australia as a country with enormous renewable energy resources, according Dr Alexandr Simonov from the Monash School of Chemistry, and the lead author of a paper published today in Nature Catalysis, which sheds new light on electrolytic water splitting.

Electrolytic water splitting: oxygen and hydrogen evolution reactions take place at the anode and cathode, which are separated by an acidic proton-conducting electrolyte

“Renewable
energy requires an energy carrier which will allow energy to be transported
around Australia and exported in the most efficient manner,” said Dr Simonov,
who is also a member of the Australian Centre for Electromaterials Science.

“In
a practical context this requires robust electromaterials – catalysts, which
can accelerate two half-reactions of the water splitting process – the hydrogen
evolution and the oxygen evolution reactions,” he said.

“Our research team has introduced an intrinsically stable, ‘self-healing’ catalytic system based on earth abundant elements to promote the water electrolysis process in a strongly acidic environment and elevated temperatures.

“The
catalyst demonstrates the state-of-the-art activity, and most importantly,
exhibits unparalleled stability under a wide range of aggressive,
technologically relevant conditions of water splitting.”

The
facilities at the Monash School of Chemistry, Monash Centre of Electron
Microscopy, Monash X-ray Platform, CSIRO and Australian Synchrotron provided
researchers with a deep understanding of the modes of operation of the
catalysts and identified pathways for future improvements.

“The
outstanding stability in the operation and the low cost of the developed
catalytic system identifies it as a potentially suitable option for use in the
industrial production of green hydrogen fuel by water electrolysis,” Dr Simonov
said.

Study co-author and ARC Laureate Fellow at the Monash School of Chemistry, Professor Doug MacFarlane said the investigation of water oxidation electrocatalysts is a core theme within the Australian Centre for Electromaterials Science, where he leads the energy program.

“It
is critically important to the rapidly developing national renewable energy
sector,” Professor MacFarlane said.

“This
work represents a breakthrough that will bring inexpensive generation of green
hydrogen from renewables much closer to reality,” he said. “It is an important
development that will further establish Australia’s role as a global powerhouse
in the generation and export of renewables.”

Dr
Simonov said water splitting in electrolysers with acidic electrolytes is most
likely to be the future of the green hydrogen production. However, the
conditions at the anodes of such devices are exceptionally harsh, making even
highly stable noble metals corrode.
“Our strategy is to provide
the means for an inexpensive catalyst to self-heal during the operation,” Dr
Simonov said.